Typically, powered devices useful for clearing debris from land may vary in size from small hand held weed trimmers to large rotatable shredding drums capable of rapidly clearing vast tracts of land. These large shredding drums typically have a plurality of cutting teeth disposed circumferentially on their outer surface. A large shredder can be powered by a chain drive, by gears or belts, or by direct drive. It may be mounted at the end of a movable boom that is driven by a diesel or gasoline engine. The shredding drum commonly encounters more than just weeds, shrubs and trees when performing its tasks. The drum may contact all manner of surface debris, such as rocks and boulders, re-bar, wire, cinder block and other materials of construction. Accordingly, the shredding operation places tremendous radial and axial stress loads on the drum, the cutting teeth, the drive shaft, and other component parts associated with the drum assembly and its operation.